Christoph Hellwig <hch@infradead.org> wrote:>> The problem we're trying to solve here is how do implement network block> devices (nbd, iscsi) efficiently. The zero copy codepath in the networking> layer does need to grab additional references to pages. So to use sendpage> we need a refcountable page. pages used by the slab allocator are not> normally refcounted so try to do get_page/pub_page on them will break.